Enforce that output files are created in primary ninja execution

Missing output files in ninja execution will be treated as errors.
Products can bypass this using the newly introduced
BUILD_BROKEN_MISSING_OUTPUTS flag.

Test: m nothing # verified missingoutfile appears in out/soong.log
Test: checkbuild passes on presubmits

Change-Id: I4eebcd08aa57fc6ccf1688c32e0d1fe06d66ab9a